Energy-related exchange-traded funds were among the worst decliners Tuesday, as traders anticipated that a government report expected Wednesday will show stocks of oil and gas are continuing to rise.

Energy traders also turned their attention away from the Nigerian strike to questions involving Venezuelan production.

Exxon Mobil

(XOM) - Get Report

and

ConocoPhillips

(COP) - Get Report

still have not come to an agreement with Venezuela's state-run oil company allowing the companies to continue to pump there. The front-month crude contract was recently down $1.22 to $67.96 a barrel.

The

PowerShares DB Oil

(DBO) - Get Report

was falling 51 cents, or 1.9%, to $26.77. The

United States Oil

(USO) - Get Report

ETF was down 96 cents, or 1.8%, to $51. The

iShares Dow Jones U.S. Oil & Gas Exploration Index

(IEO) - Get Report

was lower by 93 cents, or 1.5%, to $58.55. The

iPath S&P Crude Oil Index

(OIL) - Get Report

ETF was losing 69 cents, or 1.7%, to $37.51.

ETFs tracking silver and gold were also among the worst performers. Silver futures fell by 69 cents to $12.19 an ounce. Gold futures were losing $8.90 to $643 an ounce.

The

iShares Silver Trust

(SLV) - Get Report

was down $7.22, or 5.3%, to $121.03. The

PowerShares DB Silver

(DBS) - Get Report

ETF was down $1.35, or 5%, to $24. The

Market Vectors Gold Miners

(GDX) - Get Report

eased 92 cents, or 2.4%, to $36.93. The

iShares COMEX Gold Trust

(IAU) - Get Report

shed $1.01, or 1.4%, to $63.52.

Among winners, the

iShares Dow Jones U.S. Medical Devices

(IHI) - Get Report

was up 1.7%, thanks to headlines out of

Medtronic

(MDT) - Get Report

.

Late Monday, Medtronic said that the Supreme Court will decide whether patients can seek state court remedies against the company, even though its balloon catheter medical device won premarket approval by the Food and Drug Administration. Medtronic was higher by 1.4%, and the ETF was gaining 90 cents to $54.91.

Also in the health sector, the

Pharmaceutical HOLDRs

(PPH) - Get Report

was rising thanks to gains of 1.9% or more in holdings

Bristol-Myers Squibb

(BMY) - Get Report

,

Wyeth

(WYE)

and

Merck

(MRK) - Get Report

. The ETF was adding $1.18, or 1.5%, to $81.97.