* FTSE 100 ends up 0.1 percent
* Miners rise, banks mixed
* Indivior's collapse drags midcaps down (Adds closing prices)
LONDON, Sept 1 (Reuters) - UK blue chips, backed by buoyant mining stocks, were up for their first September trades on Friday after outperforming their European peers with a second consecutive monthly rise in August.
The FTSE 100 ended up 0.1 percent, while the mid cap FTSE 250 index was held back with a 0.1 percent retreat due to the collapse of Indivior's shares.
The drugmaker's shares sank 35 after it said it would appeal against a U.S. court ruling which potentially opens the way to a rival to the firm's Suboxone Film opiod addiction treatment.
"The company is facing a mammoth struggle now," said Neil Wilson, a senior market analyst at ETX capital.
Other midcaps suffered blows including Greene King, down 3.8 percent after HSBC cut its rating on the stock and electronics retailer Dixons Carphone, which lost 1.7 percent after both Investec and Morgan Stanley took a more negative view on its prospects.
Miners, which had already helped the FTSE stay in positive territory in the previous session, were up with Glencore rising 2.1 percent, Antofagasta 2.2 percent and Rio Tinto 0.3 percent.
Energy sector heavyweights BP and Royal Dutch Shell fell 0.1 and 0.2 percent respectively.
Financials were mixed with HSBC and Lloyds falling slightly and Barclays and Standard Chartered both up around 0.5 percent.
Provident Financial, which made the headlines in August with a profit warning and the departure of its CEO Peter Crook, saw its shares fall 1.2 percent after Jeffries cut its recommendation from 'buy' to 'hold'. (Reporting by Julien Ponthus; Editing by Richard Balmforth)