By Diane Bartz and Tom Ferraro

WASHINGTON (Reuters) - A long-negotiated patent overhaul bill sought by technology companies and opposed by big pharmaceutical makers is in deep trouble in the U.S. Senate, Democratic and Republican aides said on Monday.

Big high-tech companies such as Cisco and Hewlett-Packard began pushing for reform legislation years ago to cut the number of patent infringement lawsuits and the amount of damages paid.

A version of the bill passed the House of Representatives last September but a similar measure is stalled in the Senate amid vocal opposition from drug maker Eli Lilly & Co, seed and herbicide company Monsanto Co, and smaller tech companies that fear lower damages would leave them vulnerable to infringers.

"I wouldn't say the bill is dead, but let's say right now it's on ice," said one Democratic aide.

The measure has drawn opposition mostly from Republicans and lacks the 60 votes needed in the 100-member Senate to clear a likely procedural roadblock, aides said.

"We'll try it again next year when we will have more (Senate) Democrats," said a second Democratic aide. Democrats now control the Senate with a slim majority but are expected to add seats in the