UPDATE 1-Petro Andina recommends rejection of Pluspetrol bid

* Board rejects unsolicited bid from Pluspetrol

* Petro Andina says offer undervalues the company

TORONTO, July 3 (Reuters) - Petro Andina PAR.TO, a Canadian-based oil and gas exploration company, said on Friday its board unanimously recommends that its shareholders reject an unsolicited bid by Netherlands-based Pluspetrol Resources Corp.

Petro Andina Resources, after evaluating the offer, said it had determined that Pluspetrol was undervaluing the company.

Earlier this month, Pluspetrol Resources Corp launched a C$400 million ($348 million) bid for Petro Andina, aiming to expand its oil and gas operations in Argentina, Colombia and Trinidad.

Pluspetrol, which already has extensive production in South America, said it will bid C$8.10 in cash for each share of Petro Andina.

But, Petro Andina's have consistently traded above the offer price, since the bid was launched, indicating that investors expect a higher bid. Petro Andina's shares closed at C$9.20 Thursday on the Toronto Stock Exchange.

"This is an inadequate and opportunistic offer that fails to recognize the full value of Petro Andina," said Petro Andina President Wayne Foo, in a statement.

Petro Andina, based in Calgary, Alberta, said it has commenced an evaluation of various initiatives that are in the best interests of Petro Andina and its shareholders.

Petro Andina produces heavy oil in Argentina, and has exploration acreage in Colombia and in Trinidad and Tobago. In the first quarter, it produced 15,645 barrels of oil equivalent a day, a jump of 61 percent from a year earlier. ($1= $1.15 Canadian) (Reporting by Euan Rocha; Editing by Frank McGurty)