Shares of

Entercom Communications

(ETM) - Get Report

were among the

NYSE's

winners Monday, climbing 11% after the radio station operator posted better-than-expected first-quarter results and boosted its stock buyback program.

The company earned $7.8 million, or 19 cents a share, on revenue of $91.1 million. Excluding certain items, the company earned 18 cents a share. Analysts polled by Thomson First Call expected earnings of 14 cents a share on revenue of $90.5 million. During the year-earlier quarter, the company earned $16.2 million, or 34 cents a share, on revenue of $94.3 million.

Excluding items, the company earned 26 cents a share during the year-earlier quarter. "First-quarter results were adversely affected by sluggish advertising conditions affecting all traditional media, exacerbated by weakness in the New Orleans and Boston markets," the company said.

Looking ahead, Entercom expects second-quarter net revenue, on a same-station basis, to drop by a mid-single-digit percentage from a year ago. Station operating expenses, meanwhile, are expected to fall about 1%.

Entercom, which called its stock "significantly undervalued," said it plans to purchase an additional $100 million in stock as part of its buyback program. During the first quarter, the company bought 2.6 million shares for $77.2 million. The shares recently were trading up $3.07 to $30.69.

Park Electrochemical

(PKE) - Get Report

shares rose 11% after the maker of printed circuit materials posted fiscal fourth-quarter earnings that blew past Wall Street's expectation. For the quarter ended Feb. 26, the company reported earnings of $5.7 million, or 28 cents a share, on revenue of $57 million.

Excluding items, the company earned $10.9 million, or 54 cents a share, well above analysts' estimate of 40 cents. During the year-earlier period, the company recorded adjusted earnings of $4.9 million, or 25 cents a share, on revenue of $51.2 million. Shares were trading up $3.63 to $36.19.

Despite posting first-quarter results that were well above expectations,

Frontier Oil

( FTO) moved slightly lower Monday. The oil refiner reported earnings of $57.6 million, or $1.02 a share, up from $34.4 million, or 62 cents a share, a year earlier. Revenue jumped to $1.01 billion from $692.6 million. Analysts expected earnings of 82 cents a share on revenue of $882.6 million.

"Frontier's record results are attributable to outstanding crude oil differentials as well as wide product crack spreads," the company said. Shares recently changed hands at $63.25, down 12 cents.

Goodrich Petroleum

(GDP) - Get Report

rose 1% after the company reported better-than-expected first-quarter earnings. The oil and gas producer earned $8.6 million, or 34 cents a share, on revenue of $25.3 million. Analysts expected earnings of 13 cents a share, with revenue of $25.1 million.

During the year-earlier quarter, the company reported a loss of $6.3 million, or 30 cents a share, on revenue of $12.6 million. Shares were trading up 19 cents to $27.35.

Shares of

Holly

( HOC) rose 3% after the oil refiner's first-quarter earnings easily topped analysts' projection. The company earned $46.8 million, or $1.56 a share, on revenue of $791.6 million. Excluding a one-time gain, the company earned $31.2 million, or $1.04 a share, compared with analysts' estimate of 92 cents.

During the year-earlier quarter, Holly earned $13.6 million, or 42 cents a share, on revenue of $624.7 million. Excluding items, year-earlier earnings were $14.4 million, or 45 cents a share.

"We are very pleased with our 2006 first-quarter results, as we realized solid refined product margins, which were especially strong late in the first quarter and continuing into the second quarter," the company said. Shares were up $2.50 to $79.40.

NYSE volume leaders included

Wachovia

(WB) - Get Report

, down $3.20 to $56.19;

Golden West Financial

( GDW), up $5.49 to $76;

Lucent Technologies

( LU), down 2 cents to $2.78;

Fisher Scientific

( FSH), up $4.12 to $77.85;

Time Warner

(TWX)

, unchanged at $17.06;

Inco

(N)

, up $9.10 to $68.18;

Disney

(DIS) - Get Report

, down 12 cents to $28.97;

Thermo Electron

(TMO) - Get Report

, up 13 cents to $39.58; and

Pfizer

(PFE) - Get Report

, up 6 cents to $25.47.

Nasdaq

volume leaders included

Intel

(INTC) - Get Report

, up 52 cents to $20.03;

Sun Microsystems

(SUNW) - Get Report

, up 2 cents to $5.12;

Microsoft

(MSFT) - Get Report

, down 18 cents to $23.62;

eBay

(EBAY) - Get Report

, down 81 cents to $31.58;

Cisco Systems

(CSCO) - Get Report

, unchanged at $21.75;

JDSU

(JDSU)

, down 8 cents to $3.31;

Apple Computer

(AAPL) - Get Report

, up 65 cents to $72.54;

Sirius Satellite Radio

(SIRI) - Get Report

, up 1 cent to $4.74; and

Oracle

(ORCL) - Get Report

, down 13 cents to $14.32.