SHANGHAI, April 2 (Reuters) - China's major state-owned banks were seen selling dollars in onshore markets on Tuesday, two people with knowledge of the matter said, in an apparent attempt to prevent the Chinese currency from sinking further.

The banks stepped into the market to actively sell dollars for yuan as the local currency weakened to a 4-1/2-month low in morning deals, the people said.

It last traded at 7.2344 per dollar as of 0304 GMT.

The people declined to be identified as they were not authorised to speak publicly about market trades. (Reporting by Shanghai Newsroom; Editing by Christopher Cushing)