Shares of

Inter-Tel

(INTL) - Get Report

were among technology's winners Thursday, jumping 10% after the communications-services company received a formal buyout offer from its former chief executive.

Steven Mihaylo and investment group Vector Capital offered to buy Inter-Tel for $22.50 a share in cash, representing a 12% premium to Wednesday's closing price of $20.03. The official offer comes after Mihaylo and Vector first expressed interest in a buyout in March. In a press release, Mihaylo and Vector said the company has "raised various issues" with respect to the offer, to which they have responded. Inter-Tel shares were trading up $2.02 to $22.05.

Shares of

Lattice Semiconductor

(LSCC) - Get Report

rose 7% after the chipmaker lifted its second-quarter revenue guidance. The company now sees sequential revenue growth of 5% to 7%, up from an earlier view of 3% to 6%. Lattice attributed the higher estimate to positive quarter-to-date business trends, especially in its field-programmable gate-arrays segment. The company now sees "other income" of $4 million, up from an earlier forecast of $2.5 million, due to the liquidation of a portion of its foundry investments. Analysts polled by Thomson First Call project second-quarter revenue of $58.4 million, or sequential growth of about 2%. Shares were trading up 42 cents to $6.27.

Shares of

Radvision

( RVSN) climbed 7% after the network equipment company said it filed an application with the District Court in Tel Aviv Jaffa for the purchase of up to $30 million of its own stock. Under the proposed buyback plan, Radvision would not be able to buy more than 2 million shares. Shares were trading up $1.04 to $15.02.

Catalyst Semiconductor

(CATS) - Get Report

tumbled 14% after the maker of programmable technology products delayed the release of its fourth-quarter results for the second time in a week. The delay relates to the company's ongoing review of its financial statements and changes in cost accounting in the quarter. When the company eventually reports its results for the quarter ended April 30, it expects to report revenue of about $14 million, which is below the $16.4 million that analysts expected. A year earlier, Catalyst recorded revenue of $16.3 million. Shares were trading down 59 cents to $3.58.

Shares of

IDT

(IDT) - Get Report

rose 4% after the telecom company announced a repurchase plan of up to 25 million shares, regardless of share class. The company terminated its previous buyback authorization, which allowed the company to buy an additional 1.9 million shares of common stock and 11.7 million shares of class B stock. Shares were trading up 51 cents to $13.53.

Other technology movers included

Microsoft

(MSFT) - Get Report

, up 6 cents to $21.94;

Sun Microsystems

(SUNW) - Get Report

, up 15 cents to $4.31;

Intel

(INTC) - Get Report

, up 19 cents to $17.92;

JDSU

(JDSU)

, up 9 cents to $2.47;

Lucent Technologies

( LU), up 10 cents to $2.39;

Oracle

(ORCL) - Get Report

, up 45 cents to $13.64;

Apple Computer

(AAPL) - Get Report

, down 12 cents to $57.49;

Cisco Systems

(CSCO) - Get Report

, up 28 cents to $19.89;

Level 3 Communications

(LVLT)

, up 14 cents to $4.35;

Applied Materials

(AMAT) - Get Report

, up 19 cents to $16.63;

Sirius Satellite Radio

(SIRI) - Get Report

, down 4 cents to $4.06 and

Ciena

(CIEN) - Get Report

, up 16 cents to $4.18.