UPDATE 1-Innospec drops pursuit for UK rival Elementis after takeover approach rejection

(Adds details from Elementis statement)

April 20 (Reuters) - Innospec Inc said on Tuesday it was no longer considering a possible offer for rival Elementis after the British company rejected a 160-pence per share takeover approach from the U.S. chemicals firm.

Innospec said it had sought support from the London-listed company's board for its offer that would have valued Elementis at about 929.3 million pounds ($1.30 billion).

Elementis on Tuesday confirmed that it received Innospec's conditional cash-and-stock proposal on March 31, adding that it significantly undervalued the company.

The 175-year-old London-based company said the proposal was less attractive for its shareholders as a substantial amount of it was in the form of Innospec shares.

The news comes after Sky News on Monday reported that Elementis received a fresh takeover bid from Innospec that valued it at over 1 billion pounds, which sent shares of the British firm soaring as much as 22%.

Elementis shares, however, were trading down 0.9% at 134.3 pence by 1533 GMT. Innospec shares were down 2%. ($1 = 0.7164 pounds) (Reporting by Yadarisa Shabong, Indranil Sarkar and Vishwadha Chander in Bengaluru; Editing by Shinjini Ganguli and Ramakrishnan M.)